Medicine and new technologies
The sphenoid bone (French: Sphénoïde) forms a large part of the base of the skull in the region of the anterior and middle fossae. It is very irregular in shape, and is best described as consisting of a body, two pairs of wings, and two pairs of processes.
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The coxal (innominate) bone or hip-bone (os coxae, French: os iliaque or os coxal) is a large, irregularly shaped bone articulated behind 'with the sacrum, and in front with its fellow of the opposite side, the two bones forming the anterior and side walls of the pelvis. The coxal bone consists of three parts, named ilium, ischium, and pubis, which, though separate in early life, are firmly united in the adult. The three parts meet together and form the acetabulum (or cotyloid fossa), a large, cup-like socket situated near the middle of the lateral surface of the bone for articulation with the head of the femur.
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Eukaryotic cells possess many features that prokaryotic cells lack, including a nucleus with a double membrane that encloses DNA. In addition, eukaryotic cells tend to be larger and have a variety of membrane-bound organelles that perform specific, compartmentalized functions. Evidence supports the hypothesis that eukaryotic cells likely evolved from prokaryotic ancestors; for example, mitochondria and chloroplasts feature characteristics of independently-living prokaryotes. Eukaryotic cells come in all shapes, sizes, and types (e.g. animal cells, plant cells, and different types of cells in the body). (Hint: This a rare instance where you should create a list of organelles and their respective functions because later you will focus on how various organelles work together, similar to how your body’s organs work together to keep you healthy.) Like prokaryotes, all eukaryotic cells have a plasma membrane, cytoplasm, ribosomes, and DNA. Many organelles are bound by membranes composed of phospholipid bilayers embedded with proteins to compartmentalize functions such as the storage of hydrolytic enzymes and the synthesis of proteins. The nucleus houses DNA, and the nucleolus within the nucleus is the site of ribosome assembly. Functional ribosomes are found either free in the cytoplasm or attached to the rough endoplasmic reticulum where they perform protein synthesis. The Golgi apparatus receives, modifies, and packages small molecules like lipids and proteins for distribution. Mitochondria and chloroplasts participate in free energy capture and transfer through the processes of cellular respiration and photosynthesis, respectively. Peroxisomes oxidize fatty acids and amino acids, and they are equipped to break down hydrogen peroxide formed from these reactions without letting it into the cytoplasm where it can cause damage. Vesicles and vacuoles store substances, and in plant cells, the central vacuole stores pigments, salts, minerals, nutrients, proteins, and degradation enzymes and helps maintain rigidity. In contrast, animal cells have centrosomes and lysosomes but lack cell walls.
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Blood transfusions in humans were risky procedures until the discovery of the major human blood groups by Karl Landsteiner, an Austrian biologist and physician, in 1900. Until that point, physicians did not understand that death sometimes followed blood transfusions, when the type of donor blood infused into the patient was incompatible with the patient’s own blood. Blood groups are determined by the presence or absence of specific marker molecules on the plasma membranes of erythrocytes. With their discovery, it became possible for the first time to match patient-donor blood types and prevent transfusion reactions and deaths.
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The vagus or pneumogastric nerves are the longest of the cranial nerves, and they are remarkable for their almost vertical course, their asymmetry, and their extensive distribution, for, in addition to supplying the lung and stomach, as the name ' pneumo-gastric ' indicates, each nerve gives branches to the external ear, the pharynx, the larynx, the trachea, the oesophagus, the heart, and the abdominal viscera. They are commonly referred to as the tenth pair of cranial nerves.
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